1. Technical Field
The disclosure relates to an optical navigation device, a method of manufacturing an optical navigation device, a mobile communications device comprising an optical navigation device and a method of operating an optical navigation device.
2. Description of the Related Art
Current mobile or computer devices use a variety of different navigation mechanisms including trackball devices, multi-click joysticks and capacitance based touch areas. However, there are problems associated with each of these. Trackballs and joysticks can be unreliable and relatively expensive to implement. In addition, capacitance based touch areas do not operate satisfactorily if the finger is covered, for example by a glove, and their size can be large in relation to devices such as mobile phones and PDAs.
Optical navigation devices are also known which operate on the same principals as optical mice by comparing successive frames of an area image. However, conventional devices use LED light sources which require collimation and imaging optics which contribute to the thickness of the devices.
There is therefore a need to provide an optical navigation device which has a reduced thickness compared to existing devices and which operates in a safe manner. In addition, it is desirable that such a device can be manufactured in a simple manner and with a low part count at a suitable cost.